Concept explainers
The compound
Want to see the full answer?
Check out a sample textbook solutionChapter 24 Solutions
GENERAL CHEMISTRY-MOD.MASTERINGCHEM.
- An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of the compound gives mass percents of 31.57% C and 5.30% H. The molar mass is determined by measuring the freezing-point depression of an aqueous solution. A freezing point of 5.20C is recorded for a solution made by dissolving 10.56 g of the compound in 25.0 g water. Determine the empirical formula, molar mass, and molecular formula of the compound. Assume that the compound is a nonelectrolyte.arrow_forwardA sample of water contains 0.010 ppm lead ions, Pb2+. (a) Calculate the mass of lead ions per liter in this solution.(Assume the density of the water solution is 1.0 g/mL.) (b) Calculate the mass fraction of lead in ppb.arrow_forwardConsider three test tubes. Tube A has pure water. Tube B has an aqueous 1.0 m solution of ethanol, C2H5OH. Tube C has an aqueous 1.0 m solution of NaCl. Which of the following statements are true? (Assume that for these solutions 1.0m=1.0M.) (a) The vapor pressure of the solvent over tube A is greater than the solvent pressure over tube B. (b) The freezing point of the solution in tube B is higher than the freezing point of the solution in tube A. (c) The freezing point of the solution in tube B is higher than the freezing point of the solution in tube C. (d) The boiling point of the solution in tube B is higher than the boiling point of the solution in tube C. (e) The osmotic pressure of the solution in tube B is greater than the osmotic pressure of the solution in tube C.arrow_forward
- Sodium chloride (NaCl) is commonly used to melt ice on roads during the winter. Calcium chloride (CaCl2) is sometimes used for this purpose too. Let us compare the effectiveness of equal masses of these two compounds in lowering the freezing point of water, by calculating the freezing point depression of solutions containing 200. g of each salt in 1.00 kg of water. (An advantage of CaCl2 is that it acts more quickly because it is hygroscopic, that is. it absorbs moisture from the air to give a solution and begin the process. A disadvantage is that this compound is more costly.)arrow_forwardA 0.109 mol/kg aqueous solution of formic acid, HCOOH, freezes at −0.210 °C. Calculate the percent dissociation of formic acid.arrow_forwardThe freezing point of 0.109 m aqueous formic acid is 0.210C. Formic acid, HCHO2, is partially dissociated according to the equation HCHO2(aq)H+(aq)+CHO2(aq) Calculate the percentage of HCHO2 molecules that are dissociated, assuming the equation for the freezing-point depression holds for the total concentration of molecules and ions in the solution.arrow_forward
- Chemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage LearningChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage Learning